Cleft-lip mutations may hinder virus

More than 500 years ago, Spanish explorers settled Margarita Island, near Venezuela.  Today, 1 in every 2000 of their descendants born on the island has dry, scaly skin, brittle hair, missing or peg-shaped teeth, partial fusion of the fingers, and a cleft lip or palate.  Richard Spritz, a geneticist at the University of Colorado in Denver, thinks he knows why.